A mechanical arm for underwater operations

Abstract

The utility model discloses a kind of mechanical arms for underwater operation, including base rotary joint, shoulder joint pitch mechanism, elbow joint extension-rotation composite mechanism and wrist joint three degrees of freedom module in turn in series connection.The utility model passes through the sealing ring group cooperation of three coaxial settings and is set to the sealing groove of rotary platform output shaft, reduce leakage, improve compression resistance sealing property;The upper flange of base rotary joint is connected with the input flange of shoulder joint pitch mechanism by bolt;The output spline shaft of shoulder joint pitch mechanism is inserted into the spline sleeve of elbow joint extension-rotation composite mechanism;The output flange of elbow joint extension-rotation composite mechanism is sealed butt joint with the base flange of wrist joint three degrees of freedom module, realize joint quick disassembly, improve cooperation precision, shorten maintenance time;By setting multi-module interface assembly and double-way hydraulic connector, compression executor replacement time is shortened, and positioning accuracy is improved.

Description

Technical Field

[0001] This utility model relates to the field of robotic arm technology, and in particular to a robotic arm for underwater operations. Background Technology

[0002] Underwater operations are a high-risk, high-reward industry. In my country, underwater operations rely on humans and simple submersibles. Unmanned underwater robots can replace humans in exploration and risk assessment. However, the underwater environment is extremely complex, unpredictable, and dangerous, making it unsuitable for human operations. Currently, with the development of oceans and lakes, there is a need for underwater robotic arms to replace manual labor, enabling operations that are impossible for humans.

[0003] The existing underwater robotic arms have the following structural defects: 1. The joint housing is a welded whole, and maintenance requires cutting and damaging the structural integrity; 2. The actuator interface only has a single row of bolt holes, and replacing tools requires disassembling multiple bolts, which is time-consuming and laborious; 3. The pressure compensation pipeline is external and is easily entangled by seabed debris. Utility Model Content

[0004] This utility model discloses a robotic arm for underwater operations. It studies and improves the existing structure and its shortcomings, and provides a robotic arm for underwater operations to achieve better practical value.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A robotic arm designed for underwater operations includes a base rotary joint, a shoulder joint pitch mechanism, an elbow joint extension-rotation compound mechanism, and a wrist joint three-degree-of-freedom module connected in series.

[0007] In some embodiments, the base rotation joint is provided with a lower flange and an upper flange, and the upper flange of the base rotation joint is bolted to the input flange of the shoulder joint pitch mechanism; the output spline shaft of the shoulder joint pitch mechanism is inserted into the spline sleeve of the elbow joint telescopic-rotation composite mechanism; the output flange of the elbow joint telescopic-rotation composite mechanism is sealed and connected to the base flange of the wrist joint three-degree-of-freedom module.

[0008] In some embodiments, the base rotary joint includes a double-row crossed roller bearing, a planetary reducer, and a set of three coaxially arranged sealing rings. The outer ring of the double-row crossed roller bearing is fixed to the inner wall of the housing. The input end of the planetary reducer is connected to the motor rotor, and the output end is connected to the rotary platform. The set of three coaxially arranged sealing rings includes a Glyd ring, a magnetohydrodynamic sealing ring, and a rubber expansion ring.

[0009] In some embodiments, the shoulder joint pitching mechanism includes a second housing, a cycloidal pinwheel reducer, and a bellows compensator. The inner cavity of the second housing is provided with radial stiffeners. The input shaft of the cycloidal pinwheel reducer is connected to the output shaft of a hydraulic motor, and the free end of the bellows compensator is connected to a floating piston.

[0010] In some embodiments, the elbow joint telescopic-rotation composite mechanism includes a carbon fiber inner cylinder, a hydraulic cylinder, and a harmonic reducer, wherein the carbon fiber inner cylinder and the stainless steel outer cylinder are nested; the cylinder body of the hydraulic cylinder is fixed to the outer cylinder, and the first piston rod is connected to the carbon fiber inner cylinder; the wave generator of the harmonic reducer is connected to the motor shaft.

[0011] In some embodiments, the wrist joint three-degree-of-freedom module includes a pitch degree-of-freedom component, a yaw degree-of-freedom component, and a rotation degree-of-freedom component. The pitch degree-of-freedom component includes a miniature hydraulic cylinder, the yaw degree-of-freedom component includes a universal joint, and the rotation degree-of-freedom component includes a hollow drive shaft. The two ends of the miniature hydraulic cylinder are respectively hinged to the yaw frame and the base. The first lug of the universal joint is connected to the pitch frame. The hollow drive shaft has an optical fiber slip ring in its inner hole.

[0012] In some embodiments, a multi-module interface component is also provided, the multi-module interface component including a base plate, a hydraulic cylinder and a dual-path hydraulic connector, the end face of the base plate is provided with an annular oil groove; the end of the second piston rod of the hydraulic cylinder is connected to a wedge block; the valve core of the dual-path hydraulic connector is coaxially arranged with the base plate.

[0013] In some embodiments, the inclination angle of the wedge block is 12°±1°; the housing of the hydraulic connector is provided with a pressure balance hole.

[0014] In some embodiments, the system further includes a hydraulic gripper connected to the base plate. The gripper base of the hydraulic gripper is provided with a dovetail groove, an oil circuit interface, and an electrical connection pin. The angle of the inclined surface of the dovetail groove matches that of the wedge block. The position of the oil circuit interface corresponds to the dual-path hydraulic connector. The length of the electrical connection pin is greater than the insertion depth of the hydraulic connector.

[0015] The robotic arm for underwater operations provided by this utility model has the following advantages:

[0016] 1. By setting up a three-coaxial sealing ring assembly in conjunction with the sealing groove of the rotary platform output shaft, leakage is reduced and pressure resistance and sealing performance are improved; 2. The upper flange of the base rotary joint is bolted to the input flange of the shoulder joint pitch mechanism; the output spline shaft of the shoulder joint pitch mechanism is inserted into the spline sleeve of the elbow joint telescopic-rotation composite mechanism; the output flange of the elbow joint telescopic-rotation composite mechanism is sealed and connected to the base flange of the wrist joint three-degree-of-freedom module, realizing quick joint assembly and disassembly, improving fit accuracy, and shortening maintenance time; 3. By setting up multi-module interface components and dual-path hydraulic joints, actuator replacement time is reduced and positioning accuracy is improved. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of a robotic arm for underwater operations proposed in this utility model.

[0018] Figure 2 for Figure 1 A magnified view of a portion at point A shown;

[0019] Figure 3 This is a schematic diagram of part of the internal structure of a robotic arm for underwater operations proposed in this utility model;

[0020] Figure 4 for Figure 3 A magnified view of a portion at point B shown;

[0021] Figure 5 for Figure 3 A magnified view of a portion at point C shown.

[0022] In the attached diagram: 101, lower flange; 102, upper flange; 103, bolt; 111, first housing; 110, double-row crossed roller bearing; 120, planetary reducer; 121, motor rotor; 122, rotary platform; 130, sealing ring assembly; 131, Glyd ring; 132, magnetohydrodynamic seal; 133, rubber expansion ring; 201, input flange; 202, output spline shaft; 210, second housing; 211, radial stiffener; 220, cycloidal pinwheel reducer; 221, hydraulic motor output shaft; 230, bellows compensator; 231, floating piston; 303, spline sleeve; 3 04. Output flange; 310. Carbon fiber inner cylinder; 311. Outer cylinder; 312. First hydraulic cylinder; 313. First piston rod; 320. Harmonic reducer; 321. Wave generator; 322. Motor shaft; 404. Base flange; 410. Universal joint; 412. Pitch frame; 420. Miniature hydraulic cylinder; 421. Yaw point frame; 422. Base; 432. Tool disc; 434. Brushless motor; 501. Base plate; 510. Hydraulic cylinder; 511. Second piston rod; 512. Wedge block; 520. Dual-way hydraulic connector; 521. Valve core; 601. Gripper base. Detailed Implementation

[0023] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and marked in the accompanying drawings can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely represents selected embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] Reference Figures 1 to 5 In a preferred embodiment, a robotic arm for underwater operations includes a base rotary joint, a shoulder joint pitch mechanism, an elbow joint telescopic-rotation compound mechanism, a wrist joint three-degree-of-freedom module, and a multi-module interface assembly connected in sequence.

[0025] See also Figure 3 In some embodiments, the base rotation joint is provided with a lower flange 101 and an upper flange 102. The lower flange 101 is disc-shaped, and the upper flange 102 is annular, which are coaxially stacked above the lower flange 101. The elbow joint telescopic-rotation composite mechanism includes a telescopic cylinder and a rotation shaft. The wrist joint three-degree-of-freedom module has a pitch hinge, a yaw hinge, and a rotation shaft. The upper flange 102 of the base rotation joint is connected to the input flange 201 of the shoulder joint pitch mechanism by a first bolt 103. The output spline shaft 202 of the shoulder joint pitch mechanism is inserted into the spline sleeve 303 of the elbow joint telescopic-rotation composite mechanism. The output flange 304 of the elbow joint telescopic-rotation composite mechanism is sealed and connected to the base flange 404 of the wrist joint three-degree-of-freedom module.

[0026] See also Figure 4In some embodiments, the base rotation joint includes a double-row crossed roller bearing 110, a planetary reducer 120, and a three-coaxial sealing ring assembly 130. The outer ring of the double-row crossed roller bearing 110 is fixed to the inner wall of the first housing 111. The planetary reducer 120 is doubly fixed to the first housing 111 by radial interference fit and axial flange bolt connection, forming a torsion-bending composite support structure. The outer diameter of the planetary reducer 120 housing is interference-fitted with the mounting hole of the first housing 111. The planetary reducer 120, the motor rotor 121, and the rotary platform 122 are all disposed in the sealed cavity inside the housing 111. The motor rotor 121 is completely built into the bottom end of the first housing 111. The input end of the planetary reducer 120 is connected to the motor rotor 121, and the output end is connected to the rotary platform 122. The upper surface of the rotary platform 122 is flush with the top surface of the first housing 111. The output flange of the rotary platform 122 extends out of the first housing 111. The sealing ring assembly 130 is installed at the junction of the first housing 111 and the rotary platform 122. The three coaxially arranged sealing ring assembly 130 includes a Glyd ring 131, a magnetohydrodynamic sealing ring 132, and a rubber expansion ring 133. Specifically, the base rotary joint has a cylindrical structure. The outer ring of the double-row crossed roller bearing 110 is interference-fitted with the inner wall of the first housing 111. The Glyd ring 131 is embedded in the sealing groove of the output shaft of the rotary platform 122. The inner diameter of the Glyd ring 131 is interference-fitted with the output shaft of the rotary platform 122, and the outer diameter of the Glyd ring 131 is clearance-fitted with the inner hole of the first housing 111. Under the pressure of deep sea, the rubber matrix of the Glyd ring 131 expands under pressure, filling the micro-gap between the groove and the shaft surface. The PTFE wear-resistant layer of the Glyd ring 131 forms a sliding sealing surface with the inner hole of the first housing 111. The magnetohydrodynamic sealing ring 132 is close to the axial end face of the Glyd ring 131, and its magnetic pole spacing is 0.5 mm. The three coaxially arranged sealing ring assemblies 130 have an axial spacing of 8 mm, forming a stepped sealing barrier. Furthermore, the Gladley ring 131 has a rectangular cross-section and is interference-fitted with the first sealing groove of the output shaft of the rotary platform 122, with a pre-compression of 0.3 mm to block 90% of high-pressure seawater penetration. The annular magnetic gap width of the magnetohydrodynamic sealing ring 132 is 0.5 ± 0.02 mm, and it is installed 8 mm axially from the Gladley ring 131, with a magnetic flux density of 1.2 T and a leakage rate of <0.1 ml / h. The rubber expansion ring 133 is interference-fitted with the second sealing groove of the output shaft of the rotary platform 122 to fill the micro-gap by expanding 120% in volume upon contact with water. The motor rotor 121 has a built-in permanent magnet, and the planetary reducer 120 includes sun gear teeth and planet gear teeth. The output flange of the planetary reducer 120 is bolted to the rotary platform 122. The motor rotor 121 and the planetary reducer 120 are completely immersed in pressure-compensating oil to avoid seawater corrosion. After removing the end cover of the first housing 111, the internal transmission chain (including the rotary platform 122, motor rotor 121, and planetary reducer 120) can be taken out as a whole.

[0027] In some embodiments, the shoulder joint pitching mechanism includes a second housing 210, a cycloidal pinwheel reducer 220, and a bellows compensator 230. The second housing 210 has radial stiffeners 211 in its inner cavity. The input shaft of the cycloidal pinwheel reducer 220 is connected to the output shaft 221 of a hydraulic motor. The free end of the bellows compensator 230 is connected to a floating piston 231. The cycloidal pinwheel reducer 220 is entirely built into the sealed cavity of the second housing 210. The bellows compensator 230 is welded to the wall of the second housing 210, bridging the inner and outer cavities. The floating piston 231 is completely disposed inside the second housing 210. Specifically, the second housing 210 is a wedge-shaped cast titanium alloy structure. Its front chamber is press-fitted with a cycloidal pinwheel reducer 220. The input flange of the cycloidal pinwheel reducer 220 is bolted to the output shaft 221 of the hydraulic motor. The rear end cover is welded with a bellows compensator 230. The free end of the bellows compensator 230 extends to the outer wall of the second housing 210, and its fixed end is welded to the center of the housing wall thickness. The free end of the bellows of the bellows compensator 230 is pressurized with compensating silicone oil by a floating piston 231. The piston guide rod slides in the guide hole of the second housing 210. The cross-wall layout of the bellows compensator 230 realizes both pressure transmission (external section pressure sensing) and protection of moving parts (internal section anti-biofouling). With the precise guiding structure of the floating piston 231, the shoulder joint pitching mechanism tracks the pressure error at water depth. The radial stiffeners 211 of the second housing 210 are used to distribute the water pressure load; the cycloidal pinwheel reducer 220 amplifies the torque of the hydraulic motor by 121 times to drive the output shaft; the bellows compensator 230 compensates for the change in the volume of silicone oil in the cavity caused by water pressure / oil temperature (ΔV=0.04mL / MPa) through the displacement of the floating piston 231, so as to maintain the stability of the internal and external pressure difference.

[0028] See also Figure 5In some embodiments, the elbow joint telescopic-rotation composite mechanism includes a carbon fiber inner cylinder 310, a first hydraulic cylinder 312, and a harmonic reducer 320, with a nested structure of the carbon fiber inner cylinder 310 and the stainless steel outer cylinder 311; the cylinder body of the first hydraulic cylinder 312 is fixed to the outer cylinder 311, and the first piston rod 313 is connected to the carbon fiber inner cylinder 310; the wave generator 321 of the harmonic reducer 320 is connected to the motor shaft 322. Specifically, the carbon fiber inner cylinder 310 is a thin-walled cylindrical tube with a stainless steel flange welded to its end. It is coaxially nested within the stainless steel outer cylinder 311, with a radial gap of 0.5 mm filled with silicone grease. The front flange of the carbon fiber inner cylinder 310 is bolted to the end plate of the first piston rod 313. The rear end of the carbon fiber inner cylinder 310 is fitted with the output flange of the harmonic reducer 320 via a flange keyway. The first hydraulic cylinder 312 is a double-acting cylinder with cooling fins inside. The cylinder body of the first hydraulic cylinder 312 is connected to the rear end of the outer cylinder 311. The axis of the first piston rod 313 coincides with the center of the carbon fiber inner cylinder 310, used to push the inner cylinder 310 to extend and retract axially. The harmonic reducer 320 is a short-cylinder structure, fixed to the front cavity of the inner cylinder 310. The wave generator 321 is exposed at the cylinder end. The inner cylinder flange is fixed with a rigid wheel bolt, and the flexible wheel output flange is connected to the three-degree-of-freedom module of the wrist joint.

[0029] like Figure 2 As shown, in some embodiments, the wrist joint three-degree-of-freedom module includes a pitch degree-of-freedom component, a yaw degree-of-freedom component, and a rotation degree-of-freedom component. The pitch degree-of-freedom component includes a miniature hydraulic cylinder 420, the yaw degree-of-freedom component includes a universal joint 410, and the rotation degree-of-freedom component includes a hollow drive shaft. The two ends of the miniature hydraulic cylinder 420 are respectively hinged to the yaw frame 421 and the base 422. The first lug of the universal joint 410 is connected to the pitch frame 412. The pitch frame 412 integrates the hollow drive shaft, the third reducer, and the brushless motor 434. The inner hole of the hollow drive shaft is provided with a fiber optic slip ring. Specifically, the two ends of the miniature hydraulic cylinder 420 of the pitch degree-of-freedom component are hinged to the base 422 and the yaw frame 421 via pins, and the cylinder body of the miniature hydraulic cylinder 420 is hinged to the base 422 via a pin. The first lug of the universal joint 410 of the yaw degree-of-freedom assembly is press-fitted to the pitch frame 412, and the second lug is clearance-fitted to the base pin. The base 422 is bolted to the elbow joint output flange. The hollow shaft 430 of the rotation degree-of-freedom assembly passes through the front and rear ends of the pitch frame 412. The tool disc 432 is bolted to the front flange of the hollow drive shaft. The brushless motor 434 is independently encapsulated in the anti-leveling chamber outside the pitch frame 412. The third reducer is installed in the rear chamber of the pitch frame 412. The miniature hydraulic cylinder 420 extends and retracts to drive the pitch frame 412 to swing around the X-axis of the universal joint 410 (±110°); the universal joint 410 transmits the yaw torque to the base 422 (±180°); the hollow drive shaft integrates a fiber optic slip ring and a six-dimensional force sensor in the through hole.

[0030] In some embodiments, the multi-module interface assembly includes a base plate 501, a hydraulic cylinder 510, and a dual-path hydraulic connector 520. The base plate 501 is connected to the tool plate 432, and an annular oil groove is provided on the end face of the base plate 501. A wedge block 512 is connected to the end of the second piston rod 511 of the hydraulic cylinder 510. The valve core 521 of the dual-path hydraulic connector 520 is coaxially arranged with the base plate 501. Specifically, the base plate 501 is disc-shaped and used to raise the installation reference. The cross-section of the annular oil groove is trapezoidal and circumferentially continuous, used to collect leaked hydraulic oil and prevent it from seeping into the electrical area. Multiple hydraulic cylinders 510 are included and are evenly distributed circumferentially. The locating pin holes are evenly distributed at 120° for initial positioning of the actuator. The hydraulic pressure pushes the second piston rod 511 to drive the wedge block 512 to move radially along the 12° inclined plane and to interfere with the dovetail groove of the actuator. The valve core 521 is coaxially nested outside the electrical pin. The valve core 521 floats axially internally and automatically closes the oil circuit when disconnected. The wedge block 512 has an inclination angle of 12°±1°. The housing of the dual-path hydraulic connector 520 has a pressure balance hole. This housing is press-fitted to the base plate 501 to balance seawater pressure. The electrical pin is press-fitted to a ceramic insulator, and a temperature sensor is attached to the root of the electrical pin. The multi-module interface assembly also includes a status monitoring component, which includes a pressure sensor, a displacement probe, and a flow channel. The pressure sensor is threaded into the bottom of the annular oil groove to monitor the locking oil pressure. The displacement probe is embedded in the side hole of the wedge block 512 to detect the actuator installation. The flow channel connects the annular oil groove and the pressure sensor to achieve directional collection of leaked oil. The oil path is as follows: hydraulic oil passes through the connector valve core 521 to the annular oil groove of the base plate, then to the three-way distributor, and finally to the rodless chamber of each hydraulic cylinder 510.

[0031] In some embodiments, the system further includes a hydraulic gripper connected to a base plate 501. The gripper base 601 of the hydraulic gripper is provided with a dovetail groove, an oil circuit interface, and an electrical connection pin. A positioning pin at the bottom of the gripper base 601 is inserted into a pin hole in the base plate 501. The dovetail groove has an inclined surface angle that matches the wedge block 512. The position of the oil circuit interface corresponds to the dual-path hydraulic connector 520. The length of the electrical connection pin is greater than the insertion depth of the hydraulic connector 520. Specifically, the gripper base 601 is a U-shaped forged titanium alloy structure. A dovetail groove is opened on its top plane, which is interference-fitted with the wedge block 512 of the multi-module interface assembly. An oil circuit interface is coaxially arranged at the center of the base, and the oil circuit interface is precisely connected to the valve core 521 of the dual-path hydraulic connector 520. A 24-pin electrical connection seat is arranged in a ring array on the outer side of the oil circuit, which is clearance-fitted with the electrical pin. A positioning pin is set at the bottom of the gripper base 601 and inserted into the pin hole of the base plate 501 to achieve initial positioning.

[0032] Any content not described in detail in this specification is prior art known to those skilled in the art.

[0033] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. The substitutions may be replacements of some structures, devices, or method steps, or they may be complete technical solutions. Equivalent substitutions or modifications made based on the technical solution and inventive concept of this utility model should all be covered within the scope of protection of this utility model.

Claims

1. A robotic arm for underwater operations, characterized in that, It includes a base rotation joint, a shoulder joint pitch mechanism, an elbow joint extension-rotation composite mechanism, and a wrist joint three-degree-of-freedom module connected in series; the elbow joint extension-rotation composite mechanism includes a carbon fiber inner cylinder (310), a first hydraulic cylinder (312), and a harmonic reducer (320), and the carbon fiber inner cylinder (310) and the stainless steel outer cylinder (311) are nested in a nested structure; the cylinder body of the first hydraulic cylinder (312) is fixed to the outer cylinder (311), and the first piston rod (313) is connected to the carbon fiber inner cylinder (310); the wave generator (321) of the harmonic reducer (320) is connected to the motor shaft (322).

2. The robotic arm for underwater operations according to claim 1, characterized in that, The base rotation joint is provided with a lower flange (101) and an upper flange (102). The upper flange (102) of the base rotation joint is connected to the input flange (201) of the shoulder joint pitch mechanism by a first bolt (103). The output spline shaft (202) of the shoulder joint pitch mechanism is inserted into the spline sleeve (303) of the elbow joint telescopic-rotation composite mechanism. The output flange (304) of the elbow joint telescopic-rotation composite mechanism is sealed and connected to the base flange (404) of the wrist joint three-degree-of-freedom module.

3. The robotic arm for underwater operations according to claim 1, characterized in that, The base rotation joint includes a double-row crossed roller bearing (110), a planetary reducer (120), and a three-coaxial sealing ring assembly (130). The outer ring of the double-row crossed roller bearing (110) is fixed to the inner wall of the first housing (111). The input end of the planetary reducer (120) is connected to the motor rotor (121), and the output end is connected to the rotary platform (122). The three-coaxial sealing ring assembly (130) includes a Glyd ring (131), a magnetohydrodynamic sealing ring (132), and a rubber expansion ring (133).

4. The robotic arm for underwater operations according to claim 1, characterized in that, The shoulder joint pitching mechanism includes a second housing (210), a cycloidal pinwheel reducer (220), and a bellows compensator (230). The inner cavity of the second housing (210) is provided with radial stiffeners (211). The input shaft of the cycloidal pinwheel reducer (220) is connected to the output shaft (221) of the hydraulic motor. The free end of the bellows compensator (230) is connected to a floating piston (231).

5. The robotic arm for underwater operations according to claim 1, characterized in that, The wrist joint three-degree-of-freedom module includes a pitch degree-of-freedom component, a yaw degree-of-freedom component, and a rotation degree-of-freedom component. The pitch degree-of-freedom component includes a miniature hydraulic cylinder (420), the yaw degree-of-freedom component includes a cross-shaft universal joint (410), and the rotation degree-of-freedom component includes a hollow drive shaft. The two ends of the miniature hydraulic cylinder (420) are respectively hinged to the yaw frame (421) and the base (422). The first lug of the cross-shaft universal joint (410) is connected to the pitch frame (412). The hollow drive shaft is provided with an optical fiber slip ring in its inner hole.

6. The robotic arm for underwater operations according to claim 1, characterized in that, It also includes a multi-module interface component, which includes a base plate (501), a hydraulic cylinder (510), and a dual-path hydraulic connector (520). The end face of the base plate (501) is provided with an annular oil groove. The end of the second piston rod (511) of the hydraulic cylinder (510) is connected to a wedge block (512). The valve core (521) of the dual-path hydraulic connector (520) is coaxially arranged with the base plate (501).

7. The robotic arm for underwater operations according to claim 6, characterized in that, The inclined angle of the wedge block (512) is 12°±1°; the outer shell of the hydraulic connector (520) is provided with a pressure balance hole.

8. The robotic arm for underwater operations according to claim 6, characterized in that, It also includes a hydraulic gripper connected to the base plate (501). The gripper base (601) of the hydraulic gripper is provided with a dovetail groove, an oil circuit interface and an electrical connection pin. The angle of the inclined surface of the dovetail groove matches that of the wedge block (512). The position of the oil circuit interface corresponds to the dual-circuit hydraulic connector (520). The length of the electrical connection pin is greater than the insertion depth of the hydraulic connector (520).

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